VOL. XXV.l PHFLOSOPHICAL TRANSACTIONS. 301 



vessels in both. It is no small confirmation of this opinion, that the flesh and 

 skin felt hard, and the brain firm and solid. I might add that it is highly pro- 

 bable, that the same disposition might give a closeness or hardness to the vessels 

 every where else. It is true, this u^as a distemper; but then it is as true that it 

 is a disease of old age, and may justly be reckoned one of the effects of it. 

 And for a further proof of what I have said, I observed, that in preparing a 

 piece of the small gut for an injection, the tunica villosa felt more like a fine 

 file, than the softest velvet; and that I could use more violence in injecting the 

 vessels, than these parts will usually bear. Whoever considers how soft a sub- 

 stance an animal body is at its first beginning, and how from time to time it 

 acquires a firmness and solidity, will easily be induced to believe, that old age 

 brings a more than ordinary hardness on all the fibres and vessels. 



The necessary consequence of this hardness, and contraction of the fibres 

 and vessels of old people, is a diminution of their secretions, which, caeteris 

 paribus, are always proportional to the orifices of the glands. Hence it is that 

 we find the skin of old people always dry, their perspiration being very little. 

 They are likewise generally costive : old Bayles went to stool but once in 10 or 

 1 2 days, for some years ; and old people are always complaining of a want of 

 moisture; not that the radical moisture is dried up, but because the natural 

 secretions, by reason of the contraction of the glands, are diminished. I have 

 already observed, that we found in this old man more blood than could have 

 been expected in such an emaciated body, and doubtless it had been larger, if 

 his stomach and appetite had been as good as old Parr's. The fulness of the 

 vessels, and the frequent rheums and catarrhs of old people, evince this neces-* 

 sary consequence of the closeness of the coats of the vessels : all which agrees 

 with what the writers of institutions say, that old men are ratione partium 

 solidarum frigidi et sicci, ratione excrementorum frigidi et humidi. From this 

 retention of the excrementitious parts of the blood, we may expect all the bad 

 consequences of a vitiated plethora, and languid motion of the blood ; for the 

 fibres of the arteries being now become hard, instead of assisting, they obstruct 

 the heart in circulating the blood: and the quantity of animal spirits, separated 

 in the glands of the brain, must likewise be less, not only because of the re- 

 tention of the excrementitious humours, but also because of the closeness and 

 firmness of the brain itself; so that the contractions of the heart and all the 

 muscles must be weak, and consequently the motion of the blood languid. 

 Gelidus tardante senecta sanguis hebet. 



A due conformation of all the vital parts is most certainly necessary to bring 

 a man to a full old age ; but above all the rest, there are two which to me seem 

 to have had the greatest share in procuring a longevity to old Parr and Bayles^ 



